package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {
    /**
     * 开始时间戳
     */
    private static final long BEGIN_TIMESTAMP=1577836800L;
    private StringRedisTemplate stringRedisTemplate;
    private static int COUNT_BITS=32;

    public RedisIdWorker(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public long nextId(String keyPrefix){
        //1.生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        /**
         * 序列号位数
         */
        long timestamp=nowSecond-BEGIN_TIMESTAMP;
        //2.生成序列号
        //2.1 其获取当前日期,精确到天
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        //2.2 自增长
        Long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);
        //3.拼接并返回
        return timestamp<<COUNT_BITS | count;
    }

    public static void main(String[] args) {
        LocalDateTime time = LocalDateTime.of(2020, 1, 1, 0, 0, 0);
        long second = time.toEpochSecond(ZoneOffset.UTC);
        System.out.println("second="+second);
    }
}
